Fidaxomicin Use Remains Flat Despite Guideline Change for C difficile Treatment

The study presented at MAD-ID 2025 by Dakota Rorie, PharmD, PGY-2 pharmacotherapy resident at the Medical University of South Carolina (MUSC), examined fidaxomicin prescribing trends over 10 years. The data showed that fidaxomicin use for initial Clostridioides difficile infection (CDI) episodes rose only marginally, from 48% before the guideline update to 49% afterward (p = .830). Its use in recurrent cases also remained essentially flat (52% pre-update vs 51% post-update, p = .830), despite its preferential status in the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) recommendations.

“While we didn’t observe a statistically significant increase in fidaxomicin use, the trend toward greater use for first recurrence may suggest clinicians are slowly integrating the updated recommendations into practice,” said Rorie. “Cost may still be a limiting factor.”

The study reviewed 207 hospitalized adults with confirmed CDI who received fidaxomicin between July 31, 2014, and July 31, 2024—65 before the 2021 guidelines and 142 after. Though other outcome measures like 90-day all-cause mortality (18% vs 17%, p = .918) and recurrence or treatment failure (16% vs 8%, p = .114) showed no significant differences, researchers noted a meaningful context behind the stagnant usage rates.

“One of the things we talk about in our manuscript—which we’re still currently working on—is the influence of the ID consult service,” said Rorie. “Most of the patients we looked at had an ID consult, and if they didn’t, they usually had some other specialist involved, like GI. We think that had a pretty significant impact on fidaxomicin use.”

Rorie added that while utilization didn’t shift significantly between first and recurrent CDI cases, “we did notice an increase in overall utilization post-guideline.” She attributed this in part to specialist services “recommending fidaxomicin more now that the guidelines have positioned it ahead of vancomycin, rather than placing them on equal footing.”

A key barrier to fidaxomicin uptake is institutional formulary policy and cost. “Fidaxomicin wasn’t even added to our formulary until 2023, even though the guideline update came out in 2021,” Rorie explained. “Before that, it was frequently used as a non-formulary medication. That’s part of why we did this project.”

At MUSC, a growing health system that includes a flagship academic hospital and 11 satellite sites, cost remains a concern among prescribers. “Anecdotally, I hear a lot of providers hesitate to prescribe it because they know it’s more expensive than vancomycin,” she said. “There are concerns about whether patients can get it after discharge, and inpatient, it’s realistically hard to handle prior authorizations.”

Rorie believes that perception may be outdated. “Fidaxomicin is actually better covered now—especially since the guideline update,” she said. “Insurers are more likely to approve it, and larger institutions like ours often have access to patient assistance programs.”

When asked about strategies to improve guideline-concordant prescribing, Rorie emphasized the role of provider education. “A lot of pharmacists and providers still think of fidaxomicin as this really expensive drug that’s only used in very specific cases,” she said. “But in light of the updated IDSA guidelines, it’s something we really should be trying to push for—especially if you’re at a larger academic medical center.”

She suggested pharmacists play an active role in aligning practice with guidelines. “Pharmacists can really serve as that point person—when they see vancomycin ordered at verification, they can ask, ‘Have we considered fidaxomicin for this patient?’ That way, you can get them started inpatient and then proactively manage the outpatient aspect as well.”

Rorie also pointed to encouraging signs from broader national data. “There was a nationwide study published last October with similar findings: increased utilization, reduced recurrence, and ultimately, lower healthcare costs,” she noted. “Yes, the initial cost may be higher, but over time it could lead to reduced recurrence and lower overall costs.”

Reference

Rorie D, Hamby A, Morrisette T, Tran E, Brady L, Pettigrew A. Characterization of Fidaxomicin Use in the Real-World Setting. Abstract 104. MAD-ID Meeting. May 28–31, 2025. Orlando, FL.